[RPG] Does Eyes of the Rune Keeper allow a Warlock to cast other classes’ spells from Scrolls

dnd-5eeldritch-invocationsmagic-itemsspellswarlock

The rules for Spell Scrolls state that:

If the spell is on your class’s spell list, you can read the scroll and cast its spell without providing any material components. Otherwise, the scroll is unintelligible.

However, the description of the warlock's Eyes of the Rune Keeper eldritch invocation (PHB p. 111) states:

You can read all writing.

Therefore, the writing wouldn't be unintelligible to the warlock (because the warlock can read it). Thus, if a warlock were to be able to perform any verbal or somatic components for a spell on a spell scroll, could they cast it even if it wasn't on the warlock spell list?

Best Answer

No; reading the scroll is separate from being able to cast the spell.

The description of the spell scroll magic item begins (emphasis mine):

A spell scroll bears the words of a single spell, written in a mystical cipher.

As you note, the Eyes of the Rune Keeper eldritch invocation lets you read all writing - but that only tells you the linguistic meaning of the writing. It doesn't grant you any special ability to cast a spell that you couldn't otherwise cast. Being able to read the writing on the scroll is not the same as being able to cast the spell, and you can't cast a non-warlock spell from a scroll without having access to that class's spell list (e.g. by multiclassing).

Rules designer Jeremy Crawford unofficially confirmed this ruling in this series of tweets from March 2016 (the first part of which is also stated in the Sage Advice Compendium):

Does Eyes of the Rune Keeper work on magical runes?

Eyes of the Rune Keeper lets you read any form of writing, including the linguistic meaning of a rune, if any.

so does that mean they could read spell scrolls and cast with the normal DC for spell scroll castings?!

Nope.

While you might be able to understand the literal meaning, if any, of the words written in the "mystical cipher" on the spell scroll, that doesn't grant you the ability to cast the spell on it. For instance a scroll of knock might read "open sesame", but you still won't be able to read the spell scroll without multiclassing into bard/sorcerer/wizard, or being able to add it to your spell list some other way.